Method and apparatus for SR / BSR reporting in multi-path sidelink relay

Abstract

A relay wireless transmit / receive unit (WTRU) may receive information from at least one remote WTRU and may include an indication of a set of side link (SL) logical channels (LCHs) associated with duplicate data and an indication of a resource allocation pattern of the at least one remote WTRU. The relay WTRU may receive information from the network, which may include an indication that the SL LCH is associated with the Uu LCH. The relay WTRU may trigger a BSR (or SR) when SL LCH data associated with the Uu LCH of the relay WTRU arrives from at least one remote WTRU having a resource allocation mode of mode 2, and under conditions that at least one SL LCH from the at least one remote WTRU having a resource allocation mode of mode 2 is not associated with duplicated data.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 388,093, filed on July 11, 2022, the contents of which are incorporated herein by reference. Background Art

[0003] In dual connectivity (DC), a wireless transmit / receive unit (WTRU) is served by two nodes, each node comprising a set of cells called a master cell group (MCG) and a secondary cell group (SCG). A bearer can be associated with only an MCG or with an SCG, or it can be configured as a split bearer. Summary of the invention

[0004] A method and apparatus for scheduling request (SR) / buffer status report (BSR) reporting is disclosed. A relay wireless transmit / receive unit (WTRU) may receive information from at least one remote WTRU. The information from the at least one remote WTRU may include an indication of a set of sidelink (SL) logical channels (LCHs) associated with duplicate data and an indication of a resource allocation pattern of the at least one remote WTRU. The relay WTRU may receive information from a network, which may include an indication that the SL LCH is associated with a Uu LCH. When SL LCH data associated with the Uu LCH of the relay WTRU arrives from at least one remote WTRU having a resource allocation pattern of mode 2, and under the condition that at least one SL LCH from the at least one remote WTRU having a resource allocation pattern of mode 2 is not associated with duplicate data, the relay WTRU may trigger a BSR (or SR). The relay WTRU may determine parameters of a triggered BSR (or SR) for the Uu LCH of the relay WTRU based on the amount of data to be sent from the at least one SL LCH of the at least one remote WTRU having a resource allocation mode of mode 2, the at least one SL LCH not being associated with duplicate data. The relay WTRU may send a triggered BSR (or SR) with the determined parameters. The resource allocation mode of the remote WTRU may be mode 1 or mode 2. The information including an indication that the SL LCH is associated with the Uu LCH may be an adaptation layer configuration. The information received from the at least one remote WTRU is a PC5-Radio Resource Control (RRC) message. The relay WTRU may determine parameters of the triggered BSR (or SR) for the Uu LCH as the amount of data to be sent associated with the at least one SL LCH in the SL LCH mapped to the Uu LCH having available data. Under the condition that the relay WTRU receives an indication to cancel the BSR from the remote WTRU, the relay WTRU may cancel the BSR (or SR) for the remote WTRU data. The relay WTRU may cancel the BSR (or SR) for the remote WTRU data, conditional upon the relay WTRU receiving an indication that the remote WTRU is performing a Mode 1 transmission. The relay WTRU may determine the parameters of the triggered BSR (or SR) based on the SL LCH data from the remote WTRU that did not indicate the cancellation of the BSR (or SR). The remote WTRU may send information to the relay WTRU: when reconfigured by the network, the repetitive behavior of the remote WTRU is changed, or the remote WTRU moves in or out of coverage. The remote WTRU may determine whether to send a BSR (or SR) based on the resource allocation pattern, Uu reference signal received power (RSRP), Uu scheduling request (SR) configuration, SL measurements, or preferences from the relay WTRU. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] A more detailed understanding may be obtained from the following description given by way of example in conjunction with the accompanying drawings, in which like reference numerals indicate like elements, and in which:

[0006] Figure 1A is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented;

[0007] Figure 1B is an example of an embodiment in which Figure 1A A system diagram of an example wireless transmit / receive unit (WTRU) for use within an illustrated communication system;

[0008] Figure 1C is an example of an embodiment in which Figure 1A A system diagram of an example Radio Access Network (RAN) and an example Core Network (CN) used within the illustrated communication system;

[0009] Figure 1D is an example of an embodiment in which Figure 1A A system diagram of another example RAN and another example CN used within the illustrated communication system;

[0010] Figure 2 An example of multipath operation is shown;

[0011] Figure 3 is an example of a protocol view that splits the bearer;

[0012] Figure 4 is an example of grouped repetition;

[0013] Figure 5 is an example of a user plane protocol stack for L2 UE to network relay;

[0014] Figure 6 is an example of a control plane protocol stack for L2 UE to network relay;

[0015] Figure 7 is an example of multipath operation using the same cell;

[0016] Figure 8 is an example of multipath operation using different cells; and

[0017] Fig. 9 is an example method of triggering a SR / BSR for a relay WTRU. DETAILED DESCRIPTION

[0018] Figure 1A1 is a diagram illustrating an example communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, messaging, broadcast, etc. to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content through sharing of system resources (including wireless bandwidth). For example, the communication system 100 may employ one or more channel access methods such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA), zero tail unique word discrete Fourier transform spread OFDM (ZT-UW-DFT-S-OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multi-carrier (FBMC), etc.

[0019] like Figure 1A As shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network (CN) 106, a public switched telephone network (PSTN) 108, the Internet 110 and other networks 112, but it should be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d (any of which may be referred to as a station (STA)) may be configured to send and / or receive wireless signals and may include user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular phone, a personal digital assistant (PDA), a smart phone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable device, a head-mounted display (HMD), a vehicle, a drone, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in an industrial and / or automated process chain environment), a consumer electronic device, a device operating on a commercial and / or industrial wireless network, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0020] The communication system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node B, an evolved Node B (eNB), a Home Node B, a Home evolved Node B, a next generation Node B such as a gNode B (gNB), a new radio (NR) Node B, a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0021] The base station 114a may be part of the RAN 104, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), a relay node, etc. The base station 114a and / or the base station 114b may be configured to send and / or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in a licensed spectrum, an unlicensed spectrum, or a combination of licensed and unlicensed spectrums. A cell may provide coverage of wireless services to a specific geographic area, which may be relatively fixed or may change over time. The cell may be further divided into cell sectors. For example, a cell associated with the base station 114a may be divided into three sectors. Therefore, in one embodiment, the base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In one embodiment, the base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to send and / or receive signals in a desired spatial direction.

[0022] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0023] More specifically, as noted above, the communication system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base station 114a in the RAN 104 and the WTRUs 102a, 102b, 102c may implement a radio technology, such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), that may use Wideband CDMA (WCDMA) to establish the air interface 116. WCDMA may include communication protocols, such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High Speed ​​Uplink (UL) Packet Access (HSUPA).

[0024] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA) that may establish the air interface 116 using Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-A Pro).

[0025] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology (such as NR radio access) that may establish the air interface 116 using NR.

[0026] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may together implement LTE radio access and NR radio access, for example using dual connectivity (DC) principles. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions transmitted to / from multiple types of base stations (e.g., eNBs and gNBs).

[0027] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi)), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile Communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), etc.

[0028] Figure 1A The base station 114b in the example may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a local area, such as a business location, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a road, and the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a micro-micro cell base station or a femto cell base station. As Figure 1A As shown, the base station 114b may have a direct connection to the Internet 110. Therefore, the base station 114b may not be required to access the Internet 110 via the CN 106.

[0029] The RAN 104 may be in communication with the CN 106, which may be any type of network configured to provide voice, data, applications, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not described in detail in the accompanying drawings, the CN 106 may be configured to provide voice, data, applications, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. Figure 1AAlthough not shown in the figure, it will be appreciated that the RAN 104 and / or the CN 106 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 or a different RAT. For example, in addition to being connected to the RAN 104, which may utilize NR radio technology, the CN 106 may also be in communication with another RAN (not shown) that employs GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0030] The CN 106 may also act as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and / or the Internet Protocol (IP) in the TCP / IP Internet protocol suite. The networks 112 may include wired communication networks and / or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 or a different RAT.

[0031] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks via different wireless links). Figure 1A The illustrated WTRU 102c may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0032] Figure 1B is a system diagram illustrating an example WTRU 102. Figure 1B As shown, the WTRU 102 may include, among other things, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0033] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), any other type of integrated circuit (IC), a state machine, etc. The processor 118 may perform signal decoding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. Although Figure 1B The processor 118 and the transceiver 120 are depicted as separate components, but it is understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0034] The send / receive element 122 may be configured to send a signal to a base station (e.g., base station 114a) or receive a signal from the base station by an air interface 116. For example, in one embodiment, the send / receive element 122 may be an antenna configured to send and / or receive an RF signal. In one embodiment, the send / receive element 122 may be a transmitter / detector configured to send and / or receive, for example, IR, UV or visible light signals. In another embodiment, the send / receive element 122 may be configured to send and / or receive both RF signals and optical signals. It should be understood that the send / receive element 122 may be configured to send and / or receive any combination of wireless signals.

[0035] Although the transmit / receive element 122 Figure 1B Although depicted as a single element in the figure, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0036] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. For example, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0037] The processor 118 of the WTRU 102 may be coupled to and may receive user input data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from and store data in any type of suitable memory, such as a non-removable memory 130 and / or a removable memory 132. The non-removable memory 130 may include a random access memory (RAM), a read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from and store data in a memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0038] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel-metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0039] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to or in lieu of the information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by any suitable location-determination method while remaining consistent with an embodiment.

[0040] The processor 118 may also be coupled to other peripherals 138, which may include one or more software modules and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, module, FM radio unit, digital music player, media player, video game player module, Internet browser, virtual reality and / or augmented reality (VR / AR) device, activity tracker, etc. The peripheral device 138 may include one or more sensors. The sensor may be one or more of the following: a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor, an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, a humidity sensor, etc.

[0041] The WTRU 102 may include a full-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with specific subframes for both UL (e.g., for transmission) and DL (e.g., for reception)) may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit for reducing and / or substantially eliminating self-interference via signal processing performed by hardware (e.g., a choke) or via a processor (e.g., a separate processor (not shown) or via the processor 118). In an embodiment, the WTRU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with specific subframes for both UL (e.g., for transmission) or DL ​​(e.g., for reception)) may be concurrent and / or simultaneous.

[0042] Figure 1C 1 is a system diagram illustrating the RAN 104 and the CN 106 in accordance with an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0043] The RAN 104 may include evolved Node-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of evolved Node-Bs while remaining consistent with an embodiment. The evolved Node-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the evolved Node-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the evolved Node-B 160a, for example, may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0044] Each of the evolved Node Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, etc. Figure 1C As shown, the eNode-Bs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0045] Figure 1C The illustrated CN 106 may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (PGW) 166. Although the foregoing elements are depicted as part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0046] The MME 162 may be connected to each of the evolved Node-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, etc. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0047] The SGW 164 may be connected to each of the evolved Node-Bs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring the user plane during an inter-evolved Node-B handover, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing the context of the WTRUs 102a, 102b, 102c, and the like.

[0048] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0049] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may be in communication with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired networks and / or wireless networks owned and / or operated by other service providers.

[0050] Although the WTRU Figures 1A to 1D Although described as wireless terminals, it is contemplated that in certain representative embodiments, such terminals may (eg, temporarily or permanently) use a wired communications interface with a communications network.

[0051] In a representative embodiment, the other network 112 may be a WLAN.

[0052] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have access or an interface to a distribution system (DS) or another type of wired / wireless network that carries traffic to and / or carries traffic away from the BSS. Traffic originating from outside the BSS and going to the STA may be reached by the AP and may be delivered to the STA. Traffic originating from the STA and going to a target outside the BSS may be transmitted to the AP to be delivered to the corresponding target. Traffic between STAs within the BSS may be transmitted by the AP, for example, wherein the source STA may transmit traffic to the AP, and the AP may deliver traffic to the target STA. Traffic between STAs within the BSS may be considered and / or referred to as point-to-point traffic. Direct link establishment (DLS) may be used to transmit point-to-point traffic between the source STA and the target STA (e.g., directly between them). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunnel DLS (TDLS). A WLAN using an independent BSS (IBSS) mode may not have an AP, and STAs within or using the IBSS (eg, all STAs in the STA) may communicate directly with each other. The IBSS communication mode may sometimes be referred to herein as an "ad-hoc" communication mode.

[0053] When using the 802.11ac infrastructure operating mode or a similar operating mode, the AP may send beacons on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a dynamically set width. The primary channel may be a working channel of the BSS and may be used by the STA to establish a connection with the AP. In certain representative embodiments, carrier sense multiple access / collision avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. For CSMA / CA, a STA (e.g., each STA) (including the AP) may listen to the primary channel. If the primary channel is listened / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0054] High throughput (HT) STAs may communicate using a 40 MHz wide channel, for example, via a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels to form a 40 MHz wide channel.

[0055] Very high throughput (VHT) STA can support 20MHz, 40MHz, 80MHz and / or 160MHz wide channels. 40MHz channels and / or 80MHz channels can be formed by combining continuous 20MHz channels. 160MHz channels can be formed by combining 8 continuous 20MHz channels, or by combining two non-continuous 80MHz channels (this can be called 80+80 configuration). For 80+80 configuration, after channel coding, the data can pass through a segment parser that can divide the data into two streams. Each stream can be processed by inverse fast Fourier transform (IFFT) and time domain processing separately. These streams can be mapped to two 80MHz channels, and the data can be sent by sending STA. At the receiver of the receiving STA, the above-mentioned operation for 80+80 configuration can be reversed, and the combined data can be transmitted to the medium access control (MAC).

[0056] 802.11af and 802.11ah support operating modes below 1GHz. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah relative to those used in 802.11n and 802.11ac. 802.11af supports 5MHz, 10MHz, and 20MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1MHz, 2MHz, 4MHz, 8MHz, and 16MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support meter type control / machine type communication (MTC), such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including support for (e.g., only support for) certain bandwidths and / or limited bandwidths. MTC devices may include batteries with battery life above a threshold (e.g., to maintain very long battery life).

[0057] WLAN systems that can support multiple channels and channel bandwidths (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) include channels that can be designated as primary channels. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA (which supports the minimum bandwidth operation mode) from all STAs operating in the BSS. In the example of 802.11ah, for STAs (e.g., MTC-type devices) that support (e.g., only support) a 1MHz mode, the primary channel may be 1MHz wide, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operation modes. Carrier sensing and / or network allocation vector (NAV) settings may depend on the state of the primary channel. If the primary channel is busy, for example, because a STA (which only supports a 1MHz operation mode) is transmitting to the AP, all available bands may be considered busy even if most of the available bands remain idle.

[0058] In the United States, the available frequency band for 802.11ah is 902MHz to 928MHz. In South Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz, depending on the country code.

[0059] Figure 1D1 is a system diagram illustrating the RAN 104 and the CN 106 in accordance with an embodiment. As noted above, the RAN 104 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0060] The RAN 104 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 104 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, the gNBs 180a, 180b may utilize beamforming to send signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a may, for example, use multiple antennas to send wireless signals to and / or receive wireless signals from the WTRU 102a. In one embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on an unlicensed spectrum, while the remaining component carriers may be on a licensed spectrum. In one embodiment, the gNBs 180a, 180b, 180c may implement coordinated multi-point (CoMP) technology. For example, the WTRU 102a may receive coordinated transmissions from the gNB 180a and gNB 180b (and / or gNB 180c).

[0061] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with a set of parameters that may be scalable. For example, OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or transmit time intervals (TTIs) of varying or scalable lengths (e.g., containing varying numbers of OFDM symbols and / or varying absolute time lengths over time).

[0062] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c while not accessing other RANs (e.g., such as the eNodeBs 160a, 160b, 160c). In a standalone configuration, the WTRUs 102a, 102b, 102c may use one or more of the gNBs 180a, 180b, 180c as mobility anchor points. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate / connect with the gNB 180a, 180b, 180c while also communicating / connecting with another RAN, such as the eNodeB 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement the DC principle to communicate with one or more gNBs 180a, 180b, 180c and one or more eNodeBs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNodeB 160a, 160b, 160c may act as a mobility anchor for the WTRUs 102a, 102b, 102c, and the gNB 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0063] Each of the gNBs 180a, 180b, 180c may be associated with a specific cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in UL and / or DL, support of network slicing, interworking between DC, NR and E-UTRA, routing of user plane data towards user plane functions (UPFs) 184a, 184b, routing of control plane information towards access and mobility management functions (AMFs) 182a, 182b, etc. Figure 1D As shown, gNBs 180a, 180b, and 180c may communicate with each other via an Xn interface.

[0064] Figure 1D The illustrated CN 106 may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b, and possible data networks (DNs) 185a, 185b. Although the aforementioned elements are depicted as part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0065] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via the N2 interface and may act as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRU 102a, 102b, 102c, support of network slicing (e.g., handling of different protocol data unit (PDU) sessions with different requirements), selecting a specific SMF 183a, 183b, management of registration areas, termination of non-access stratum (NAS) signaling, mobility management, etc. The AMF 182a, 182b may use network slicing in order to customize CN support for the WTRU 102a, 102b, 102c based on the type of services utilized by the WTRU 102a, 102b, 102c. For example, different network slices may be established for different use cases, such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for MTC access, etc. The AMF 182a, 182b may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies, such as WiFi.

[0066] The SMF 183a, 183b may be connected to the AMF 182a, 182b in the CN 106 via the N11 interface. The SMF 183a, 183b may also be connected to the UPF 184a, 184b in the CN 106 via the N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b, and configure the traffic routing through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy implementation and QoS, providing DL data notification, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0067] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via the N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering DL packets, providing mobility anchoring, etc.

[0068] The CN 106 may facilitate communications with other networks. For example, the CN 106 may include or may communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired networks and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to the DNs 185a, 185b via the UPFs 184a, 184b via the N3 interfaces to the UPFs 184a, 184b and the N6 interfaces between the UPFs 184a, 184b and the local DNs 185a, 185b.

[0069] Given that Figures 1A to 1D as well as Figures 1A to 1D Corresponding to the description of the present invention, one or more or all of the functions described herein with reference to one or more of the following items may be performed by one or more simulation devices (not shown): WTRU102a to 102d, base station 114a to 114b, evolved Node B 160a to 160c, MME 162, SGW 164, PGW 166, gNB180a to 180c, AMF 182a to 182b, UPF 184a to 184b, SMF 183a to 183b, DN 185a to 185b and / or any other device described herein. The simulation device may be one or more devices configured to mimic one or more or all of the functions described herein. For example, the simulation device can be used to test other devices and / or simulate network and / or WTRU functions.

[0070] The simulation device may be designed to implement one or more tests of other devices in a laboratory environment and / or in an operator network environment. For example, one or more simulation devices may perform one or more functions or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. One or more simulation devices may perform one or more functions or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The simulation device may be directly coupled to another device for the purpose of testing and / or performing tests using over-the-air wireless communications.

[0071] One or more simulation devices can perform one or more (including all) functions without being implemented / deployed as part of a wired and / or wireless communication network. For example, the simulation device can be used in a test scenario in a test laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network to implement testing of one or more components. One or more simulation devices can be test equipment. Direct RF coupling and / or wireless communication via an RF circuit system (e.g., which can include one or more antennas) can be used by the simulation device to send and / or receive data.

[0072] Figure 2 An example of multipath operation that may include a remote WTRU, a relay WTRU, and a network is shown. The remote WTRU may be in resource allocation mode 2 for sidelink (SL) transmission and may include split bearers with duplication, where the same data is sent to two paths (e.g., to the network and to the relay WTRU). For this path from the remote WTRU to the relay WTRU for duplicate data, the relay WTRU does not require a buffer status report (BSR). The remote WTRU may also include split bearers without duplication, where data is sent only on one path (e.g., to the network or to the relay WTRU). The SDAP layer provides N:1 bearer mapping. The SDAP may be located in both the remote WTRU and the relay WTRU between the PDCP layer and the RLC layer. In the relay WTRU, the SDAP may be used to determine the routing between the input RLC channel and the output RLC channel. The relay WTRU receives data from the remote WTRU.

[0073] The relay WTRU may determine whether to trigger a scheduling request (SR) and / or a buffer status report (BSR) based on the scheduling or resource allocation pattern indicated by the remote WTRU and the repetition status of the LCH.

[0074] The relay WTRU may receive information about a set of sidelink (SL) logical channels (LCHs) associated with repeated data from the remote WTRU.

[0075] The relay WTRU may receive information about the mapping, association or correspondence between the SL LCH and the Uu LCH from the network. This information may be an adaptation layer configuration.

[0076] The relay WTRU may receive an indication of a resource allocation mode (eg, Mode 1 or Mode 2) from a remote UE.

[0077] Under the condition that at least one remote WTRU is configured with mode 2 and is mapped to a Uu LCH with available data or at least one of the SL LCHs associated with the Uu LCH is not associated with duplicate data, the relay WTRU may trigger an SR / BSR when data arrives at the relay Uu LCH.

[0078] The relay WTRU may determine the buffer status report for the Uu LCH as the amount of data to be sent associated with the mapped SL LCHs that are not associated with duplicate data and are associated with Mode 2 transmissions from the remote WTRU.

[0079] Figure 3 The protocol view of the split bearer is shown. The WTRU may have a Packet Data Convergence Protocol (PDCP) entity associated with it, and the peer PDCP entity on the network side may terminate at one of the gNBs (i.e., primary gNB or secondary gNB). In the downlink, the core network (CN) may provide a packet data convergence protocol (PDCP) entity to the gNB where the PDCP is terminated (e.g., primary gNB or secondary gNB). Figure 3 The network can send data via gNB (e.g., Figure 3 The link between gNB1) and WTRU in the gNB may send data directly to the WTRU, or may forward the PDCP PDU to gNB2 (e.g., via an Xn interface), and gNB2 may send data to the WTRU via the link between the gNB and the WTRU.

[0080] In the uplink, the WTRU may be configured with one of the paths as the primary path and the other path as the secondary path. A threshold may be configured, such as a UL split buffer threshold. If the uplink buffer size of the bearer is less than the threshold, the PDCP may send data only to the Radio Link Control (RLC) associated with the primary path. If the buffer size becomes greater than the threshold, the WTRU may send data to either path (i.e., this may be left to the WTRU implementation).

[0081] Figure 4 An example of packet repetition is shown. When repetition is configured for a radio bearer by radio resource control (RRC), at least one auxiliary RLC entity may be added to the radio bearer to handle repeated PDCP PDUs, such as Figure 4 As shown. The logical channel corresponding to the primary RLC entity may be referred to as the primary logical channel, and the logical channel corresponding to one or more secondary RLC entities may be referred to as one or more secondary logical channels. All RLC entities involved in the repetition may have the same RLC mode. Repetition at the PDCP includes submitting the same PDCP PDU multiple times: once to each activated RLC entity of the radio bearer. Packet repetition increases reliability and reduces latency by utilizing multiple independent transmission paths, and is particularly beneficial for URLLC services. The PDCP control PDU may not be repeated and may always be submitted to the primary RLC entity.

[0082] When repetition for a data radio bearer (DRB) is configured, the RRC may set the state of the PDCP repetition (e.g., activated or deactivated) upon configuration or reconfiguration. After configuration, the PDCP repetition state may be dynamically controlled, for example, by means of a MAC control element. In dual connectivity (DC), the WTRU may apply MAC CE commands regardless of their source (e.g., from the MCG or SCG).

[0083] When repetition is configured for a sidelink radio bearer (SRB), the state is active and may not be dynamically controlled. When repetition is configured for a DRB with more than one secondary RLC entity, the RRC may set the state of each of these secondary RLC entities (i.e., activated or deactivated). Subsequently, the MAC CE may be used to dynamically control whether each configured secondary RLC entity for the DRB should be activated or deactivated (i.e., which RLC entities should be used for repeated transmission). The primary RLC entity may not be deactivated. When repetition is deactivated for a DRB, all secondary RLC entities associated with this DRB may be deactivated. When a secondary RLC entity is deactivated, it may not be rebuilt, the HARQ buffer may not be refreshed, and the sending PDCP entity may instruct the secondary RLC entity to discard all duplicate PDCP PDUs.

[0084] When repetition is activated for a DRB, the network may ensure that at least one serving cell is activated for each logical channel associated with the activated RLC entity for the DRB. When deactivation of a secondary cell (SCell) leaves no serving cell activated for a logical channel for the DRB, the network shall ensure that repetition is also deactivated for the RLC entity associated with the logical channel.

[0085] When repetition is activated, the original PDCP PDU and the corresponding repetition shall not be sent on the same carrier. Logical channels configured with repeated radio bearers may belong to the same MAC entity (referred to as Carrier Aggregation (CA) repetition) or to different MAC entities (referred to as Dual Connectivity (DC) repetition).

[0086] When repetition on more than two RLC entities is configured for a radio bearer, CA repetition may also be configured in either or both of the MAC entities together with DC repetition. In CA repetition, logical channel mapping restrictions may be used in the MAC entity to ensure that different logical channels of a radio bearer in the MAC entity are not sent on the same carrier. When CA repetition is configured for an SRB, one of the logical channels associated with the SRB may be mapped to a specific cell (SpCell).

[0087] When CA repetition is deactivated for DRB in the MAC entity (i.e., none or only one of the RLC entities of the DRB in the MAC entity remains activated), the logical channel mapping restriction of the logical channel of the DRB can be lifted as long as CA repetition remains deactivated for the DRB in the MAC entity.

[0088] When the RLC entity confirms the transmission of the PDCP PDU, the PDCP entity shall indicate to other RLC entities to discard the PDCP PDU. In case of CA repetition, when the RLC entity limited to the SCell reaches the maximum number of retransmissions of the PDCP PDU, the WTRU may notify the gNB but does not trigger a Radio Link Failure (RLF).

[0089] Consider SL-based UE-to-network relay. Sidelink relay may be used to support 5G ProSe UE-to-network relay (U2N relay) functionality to provide connectivity to the network for U2N remote WTRUs. Both L2 and L3 U2N relay architectures may be supported. In addition to controlling the sidelink resources, the L3U2N relay architecture may be transparent to the serving RAN of the U2N relay WTRU. The U2N relay WTRU shall be in RRC_CONNECTED state to perform relay of unicast data.

[0090] For L2 U2N relay operation, the following RRC state combinations may be supported: (1) both the U2N relay WTRU and the U2N remote WTRU shall be in the RRC connected state to perform transmission / reception of relayed unicast data; and (2) the U2N relay WTRU may be in the RRC_IDLE, RRC_INACTIVE or RRC_CONNECTED state as long as all U2N remote WTRUs connected to the U2N relay WTRU are in the RRC_INACTIVE or RRC_IDLE state.

[0091] For L2 U2N relay operation, the U2N remote WTRU may only be configured to use resource allocation mode 2 for data to be relayed.

[0092] A single unicast link may be established between one L2 U2N relay WTRU and one L2 U2N remote WTRU.The traffic of the U2N remote WTRU and the traffic of the U2N relay WTRU via a given U2N relay WTRU should be separated in different Uu RLC channels on the Uu interface.

[0093] Figure 5 An example of a user plane (UP) protocol stack for L2 U2N relay is shown in FIG. Figure 6An example of a control plane (CP) protocol stack for L2U2N relay is shown. The Sidelink Relay Adaptation Protocol (SRAP) sublayer is placed above the RLC sublayer for both the control plane and the user plane at both the PC5 interface and the Uu interface. The Uu SDAP, PDCP, and RRC terminate between the L2U2N Remote WTRU and the gNB, while the SRAP, RLC, MAC, and PHY terminate in each hop (i.e., the link between the L2 U2N Remote WTRU and the L2 U2N Relay WTRU and the link between the L2U2N Relay WTRU and the gNB).

[0094] For L2 U2N relay operation, the SRAP sublayer on the PC5 hop may be used for bearer mapping purposes. There is no SRAP sublayer on the PC5 hop for relaying messages for L2U2N remote WTRUs on the Broadcast Control Channel (BCCH) and the Physical Control Channel (PCCH). For messages for L2U2N remote WTRUs on SRB0, there is no SRAP sublayer on the PC5 hop, but there is a SRAP sublayer on the Uu hop for both downlink and uplink.

[0095] For L2 U2N relay operation, for the uplink, the Uu SRAP sublayer supports uplink bearer mapping between the ingress PC5 relay RLC channel for relaying and the egress Uu relay RLC channel over the L2U2N relay WTRU Uu interface. For uplink relay traffic, different end-to-end RBs (e.g., SRBs or DRBs) of the same remote WTRU and / or different remote WTRUs may be multiplexed on the same Uu relay RLC channel.

[0096] For L2 U2N relay operation, for the uplink, the Uu SRAP sublayer supports L2 U2N remote WTRU identification for UL traffic. The identification information of the L2 U2N remote WTRU Uu radio bearer and the local remote WTRU ID may be included in the Uu SRAP header in the uplink so that the gNB can associate received packets for a specific PDCP entity associated with the correct remote WTRU Uu radio bearer of the remote WTRU.

[0097] For L2 U2N relay operation, for the uplink, the PC5 SRAP sublayer at the L2 U2N remote WTRU supports uplink bearer mapping between the remote WTRU Uu radio bearers and the egress PC5 relay RLC channels.

[0098] For L2 U2N relay operation, for the downlink, the Uu SRAP sublayer supports downlink bearer mapping at the gNB to map the end-to-end radio bearers (e.g., SRBs, DRBs) of the remote WTRU into the Uu relay RLC channel over the relay WTRU interface. The Uu SRAP sublayer supports downlink bearer mapping and data multiplexing between multiple end-to-end radio bearers (e.g., SRBs or DRBs) of the L2 U2N remote WTRU and / or different L2 U2N remote WTRUs and one Uu relay RLC channel over the relay WTRU Uu interface.

[0099] For L2 U2N relay operation, for the downlink, the Uu SRAP sublayer supports remote WTRU identification for downlink traffic. The identification information of the remote WTRU Uu radio bearer and the local remote WTRU ID may be included in the Uu SRAP header by the gNB in ​​the downlink so that the relay WTRU maps packets received from the remote WTRU Uu radio bearer to its associated PC5 relay RLC channel.

[0100] For L2 U2N relay operation, for the downlink, the PC5 SRAP sublayer at the relay WTRU supports downlink bearer mapping between the ingress Uu relay RLC channel and the egress PC5 relay RLC channel.

[0101] For L2 U2N relay operation, for the downlink, the PC5 SRAP sublayer at the remote WTRU may correlate received packets for a specific PDCP entity associated with the correct Uu radio bearer of the remote WTRU based on the identification information included in the UuSRAP header.

[0102] The Local Remote WTRU ID may be included in the PC5 SRAP header and the Uu SRAP header. The L2 U2N relay WTRU may be configured by the gNB with a Local Remote WTRU ID to be used in the SRAP header. The Remote WTRU may obtain the Local Remote ID from the gNB via Uu RRC messages including, for example, RRCSetup, RRCReconfiguration, RRCResume, and RRCReestablishment. In both the PC5 hop and the Uu hop, the Uu DRBs and Uu SRBs may be mapped to different PC5 relay RLC channels and Uu relay RLC channels.

[0103] The gNB may be responsible for avoiding conflicts in the use of the Local Remote WTRU ID. The gNB may update the Local Remote WTRU ID with the updated Local Remote ID via a message to the relay WTRU (e.g., RRCReconfiguration message). The serving gNB may perform the Local Remote WTRU ID update independently of the PC5 unicast link L2 ID update procedure.

[0104] The sidelink supports scheduling or resource allocation Mode 1 and Mode 2. For a WTRU within coverage, the gNB can control whether the WTRU transmits using Mode 1 or Mode 2.

[0105] In Mode 1 scheduling available for sidelink WTRUs in RRC_CONNECTED state, the WTRU may receive a SL grant directly from the network, for example in downlink control information (DCI). In this case, the WTRU may report the buffer status for SL data grouped by destination index. The destination index may correspond to a unique L2 destination ID or a pair of source / destination L2 IDs. If a SL grant is not available for transmission of pending data, the WTRU may report a SL SR.

[0106] In Mode 2 scheduling, which may be used by a WTRU in any RRC state or a WTRU out of coverage, a WTRU may be configured with a resource pool from which it may perform autonomous resource selection and scheduling. Resources may be selected by the WTRU based on information (i.e., sensing results) in previous sidelink control information (SCI) transmissions of other WTRUs.

[0107] The primary use case considered for Layer 2 WTRU to Network (NW) Relay is when the remote WTRU is out of coverage. With multipath, the remote WTRU may be assumed to be in coverage and may therefore utilize the Uu path, the SL (relay) path, or both. Solutions with multipath support may enhance reliability and throughput (e.g., by switching between multiple paths or utilizing multiple paths simultaneously) in the following scenarios [RAN2, RAN3]: The WTRUs may be connected to the same gNB via: Layer 2 WTRU to Network Relay using one direct path and one indirect path via scenario (1) or via another WTRU via scenario (2) (where WTRU-WTRU interconnection is assumed to be ideal). The solution used for scenario (1) may be reused for scenario (2) without excluding the possibility of not including parts of the solution that are not necessary for scenario (2) operation.

[0108] In multipath operation, the direct link between the remote WTRU and the gNB and the backhaul link between the relay WTRU and the gNB may be served by the same gNB, or by the same cell of the same gNB. If Mode 1 is used for scheduling of the SL between the remote WTRU and the relay WTRU, the scheduling of all links (e.g., Uu between the remote WTRU and the gNB, backhaul Uu between the relay WTRU and the gNB, and SL between the remote WTRU and the relay WTRU) may be done by the gNB. If Mode 2 is used and the gNB pre-configures the resource pools for the SLs that the remote WTRU can use autonomously, the gNB can still be the gNB that decides the resource pool configuration and therefore has control over the scheduling on the SL, even if it is not in real time as in the case of Mode 1.

[0109] From a protocol architecture perspective, multipath can be modeled similarly to DC, as different MAC entities are used for the Uu link and SL, and the same PDCP entity is configured for a given bearer using multipath (e.g., split bearer). However, if the same gNB is serving the cells for both Uu and SL, this case can be considered similar to the CA case. However, in CA, one MAC entity is utilized, which is not the case here. Even more complicated, Uu and SL can be served by the same cell of a given gNB (i.e., not even CA).

[0110] Figure 7 and Figure 8 An example showing how multipath can be modeled at the protocol level.

[0111] Figure 7 An example of multipath operation using the same cell is shown. The WTRU includes a split bearer with a Uu direct path to cell / scheduler 1 and a SL path to a relay WTRU. The relay WTRU has a Uu path to cell / scheduler 1.

[0112] Figure 8 An example of multipath operation using different cells is shown. The WTRU includes a split bearer with a Uu direct path to cell / scheduler 1 and a SL path to a relay WTRU. The relay WTRU has a Uu path to cell / scheduler 2.

[0113] Multipath may involve the same scheduler controlling the Uu and SL paths of the remote WTRU or even the Uu path of the relay WTRU. Depending on the SL scheduling mode of the remote WTRU, the relay WTRU may end up triggering a redundant SR / BSR procedure. For example, if the SL scheduling mode is Mode 1, the remote WTRU may send a BSR for the data to be scheduled on the SL, and when this data arrives at the relay WTRU, the relay WTRU may send another BSR related to the same data that the gNB just scheduled on the SL to obtain a grant on the backhaul Uu. In addition, at the remote WTRU, the SL BSR and the Uu BSR may be redundant for duplicate data. For example, if packet repetition is to be applied and Mode 1 scheduling is used on the SL, the remote WTRU may send one Uu BSR and another SL BSR to the same gNB for the same data since the MAC entities for Uu and SL are separate.

[0114] Therefore, new SR / BSR procedures may be needed in case of multipath to avoid unnecessary Uu overhead.

[0115] The embodiments described herein may apply when multipath behavior is configured on the same cell or on different cells of the same gNB. In some embodiments, the WTRU may perform the behavior applicable to multipath only if it is configured to perform the behavior or only if the WTRU can confirm that both links have the same scheduler.

[0116] The remote WTRU may send a repetition indication to the network. The repetition indication may be sent using an RRC message. The repetition indication may contain a list of LCHs / bearers and the corresponding repetition status of the LCHs / bearers. The repetition indication may be sent using a MAC CE. For example, the remote WTRU may send a repetition status (e.g., enabled / disabled) with each LCH or LCG reported in the BSR. In one embodiment, the WTRU may indicate to the network that repetition is enabled or disabled for one or more specific bearers. The WTRU may indicate which bearer or bearers have repetition enabled or disabled. The WTRU may send such an indication when it determines to enable or disable repetition.

[0117] The remote WTRU may be configured with a correspondence between a SL logical channel (LCH) / logical channel group (LCG) and a Uu LCH / LCG. The WTRU may receive information about the correspondence between a Uu LCH and a SL LCH and / or between a Uu LCG and a SL LCG. This correspondence may indicate whether the LCH or LCG is being used to send duplicate data. Considering the need to avoid sending redundant BSRs, this correspondence may be used to determine whether to send a SL or Uu BSR for a LCH or LCG, as described herein. The WTRU may explicitly receive this correspondence information from the network (e.g., in RRC signaling). The WTRU may pre-configure or pre-specify using this correspondence information. The network may turn on or off repetitions between pre-specified Uu LCH and SL LCH or Uu LCG and SL LCG.

[0118] The remote WTRU may receive signaling (e.g., MAC CE, DCI, or RRC message) from the network to turn on or off repetition between the configured or pre-specified SL and Uu LCH with a corresponding relationship. Such signaling may enable or disable repetition across all configured / pre-specified LCHs or only a subset of LCHs, which may be indicated in the signaling itself.

[0119] The remote WTRU may report one or both of the SL BSR or the Uu BSR for repetition. In one embodiment, the WTRU may use the Uu BSR or the SL BSR to report the BSR of the LCH associated with repetition on the SL (relay) path and the Uu (direct) path. Herein, the BSR of the LCH associated with repetition may be referred to as the repetition BSR, and the repetition LCH may refer to the LCH associated with the bearer in which repetition is configured and / or activated. If the buffer status contains or includes PDUs that have been repeated on both the Uu path and the SL path, the WTRU may report the BSR on only one link. If the WTRU is configured with or receives information about the correspondence between Uu and SLLCH, and repetition is enabled for a pair of LCHs, the WTRU may report the BSR of one of the links only for the LCH configured with the correspondence.

[0120] The WTRU may determine whether to include the buffer status regarding duplicate data in the Uu BSR or the SL BSR or both based on one or a combination of rules or conditions. In one embodiment, the WTRU may report the BSR via Uu or SL based on a determination of a first condition related to Uu and / or SL. If the first condition for reporting the BSR to both Uu and SL is met, the WTRU may determine whether to report the BSR via Uu or via SL based on a second condition. For example, the WTRU may use the first condition to determine whether to report the BSR regarding the duplicate BSR via both Uu and SL. In the event that the first condition is not met and it will report using the BSR of only one of the two links, the WTRU may determine the link to use based on the second condition.

[0121] The WTRU may use any one or a combination of the following rules or conditions, which may be used as condition 1 or condition 2 in the above embodiments.

[0122] The WTRU may use rules or conditions based on the need to report a SL BSR or a Uu BSR that may be associated with a non-duplicate LCH. For example, the WTRU may report a BSR associated with a duplicate LCH via a link (e.g., Uu or SL) for which the WTRU has a buffer status to report associated with a non-duplicate LCH.

[0123] The WTRU may use rules or conditions based on a configuration associated with the bearer or the WTRU itself. For example, the WTRU may be configured to report a BSR via Uu or SL based on a configuration that may pertain to a bearer that is duplicated. For example, a bearer may be configured with a primary path and the WTRU may report a BSR via the path configured as the primary path. For example, the WTRU may be configured to report a BSR via Uu or SL or to prioritize the reporting of a BSR.

[0124] The WTRU may use rules or conditions associated with the quality of the Uu link and / or the SL link. For example, if the Uu reference signal received power (RSRP) is above a threshold, the WTRU may report a duplicate BSR in the Uu RSRP. For example, if the Uu RSRP is below a threshold, the WTRU may report a duplicate BSR in both the Uu BSR and the SL BSR.

[0125] The WTRU may use rules or conditions associated with SR triggering. For example, if the WTRU triggers a Uu or SL SR, it may report the available data in the BSR for the same link (ie, Uu / SL).

[0126] The WTRU may use rules or conditions associated with the need to trigger an SR and / or the availability of uplink resources to report a BSR. For example, if the WTRU may use an uplink grant to include a Uu BSR and / or if Uu BSR reporting may be performed without triggering an SR, the WTRU may report a repeated BSR via Uu.

[0127] The WTRU may use rules or conditions based on the priority of the SL and / or Uu LCH. For example, the WTRU may report a repeat BSR via Uu or SL based on the SL priority and / or Uu priority. The WTRU may compare the priority to a threshold and may report a repeat BSR via Uu or SL if it determines that the priority is above or below the threshold.

[0128] The WTRU may use rules or conditions based on the prioritized BSR in the MAC layer. For example, if the duplicate LCH on the SL is associated with or included with a prioritized SL BSR MAC CE (i.e., they are included first in the grant), the WTRU may report the duplicate BSR as a SL BSR. For example, if the duplicate SL LCH is a prioritized SLLCH, the WTRU may report the duplicate BSR in the SL BSR. Otherwise, the WTRU may report the duplicate BSR in the Uu BSR.

[0129] The WTRU may use fixed rules or conditions. For example, the WTRU may report duplicate BSRs in the Uu BSR. The advantage of this approach is that it reduces the overhead of BSR reporting for duplicate data because the L2 ID does not need to be reported.

[0130] The WTRU may use rules or conditions based on the granted space availability. For example, if there is not enough space to report a duplicate BSR in the SL BSR, the WTRU may report a duplicate BSR in the Uu BSR, otherwise the WTRU may report a duplicate BSR in the SL BSR. For example, if there is enough space to report a duplicate BSR in both the SL BSR and the Uu BSR, the WTRU may report a duplicate BSR in both the Uu BSR and the SL BSR. Otherwise, if there is not enough space to report a duplicate BSR in both the SL BSR and the Uu BSR, the WTRU may report the duplicate SR in only one of the BSR MAC CEs and may decide which one based on other rules or conditions in this document.

[0131] When the WTRU decides to report the duplicate buffer status via only one link, it may discard or remove the BSR of the associated duplicate LCH on the other link. For example, if the duplicate buffer status is reported via the SL BSR, the WTRU may cancel the Uu BSR. For example, if the duplicate buffer status is reported via the Uu BSR, the WTRU may cancel the SL BSR. For example, if the duplicate buffer status is reported via the SL BSR, the WTRU may remove the duplicate buffer status from the Uu BSR report. For example, if the duplicate buffer status is reported via the Uu BSR, the WTRU may remove the duplicate buffer status from the SL BSR. The WTRU may indicate to the network (e.g., using a flag in the BSR or another MAC CE) that the WTRU reports duplicate BSRs only in the BSR associated with one link (i.e., the Uu BSR or the SL BSR). For example, the WTRU may use a Uu / SL LCH for a bearer that may be repeated once, but use the same LCH for data associated with bearers that are not repeated. When reporting a BSR for this LCH, the WTRU may indicate when the BSR is reported that the repetition is associated with this LCH.

[0132] In one embodiment, when reporting the BSR associated with the first link, the BSR associated with the duplicate link may be downgraded. For example, the logical channel priority (LCP) of the downgraded BSR may be such that the BSR may be sent at a lower priority.

[0133] The WTRU may trigger a BSR when the repetition status of one or more LCHs changes (eg, from repetition activated to deactivated, or vice versa).

[0134] Any combination of the above actions for the WTRU may be performed.

[0135] A remote WTRU may trigger a Uu SR or a SL SR. When data arrives for an LCH (e.g., Uu or SL) associated with a repetition, the WTRU may trigger a Uu SR or a SL SR or both. In one embodiment, when data arrives for an LCH associated with a repetition, the WTRU may trigger a Uu SR or a SL SR. When data arrives on a bearer configured with repetitions, the WTRU may be configured with or receive information about rules or conditions for triggering a Uu SR or a SL SR. For example, the WTRU may trigger a SR for which the RLC entity first receives the data. For example, the WTRU may trigger a SR for which its SR resources (e.g., SL SR or Uu SR) appear first in time. For example, the WTRU may trigger a Uu SR or a SL SR based on a configured preference from the network. For example, the WTRU may trigger a specific SR based on the presence of other (e.g., non-repetitive) data available for transmission. For example, if other data available for transmission is buffered at the WTRU on Uu, the WTRU may trigger a Uu SR instead of a SL SR for the repeated data. For example, if the amount of Uu buffered data is greater than the amount of SL buffered data, the WTRU may trigger a Uu SR. For example, the WTRU may trigger a specific SR (e.g., Uu or SL) based on a comparison of the Uu SL LCH associated with the duplicate bearer, which may be compared to a threshold. The WTRU may trigger a Uu SR if the Uu LCH priority is greater than a configured threshold. The WTRU may trigger a SL SR if the SL LCH priority is greater than a configured threshold. The WTRU may trigger a Uu SR if the Uu LCH priority is above a first threshold, or the SL LCH is below a second threshold, otherwise it may trigger a SL SR.

[0136] Once a SR (e.g., SL or Uu) is triggered, the WTRU may cancel the other SR. For example, if the WTRU triggers a SL SR, it may cancel the Uu SR. For example, if the WTRU triggers a Uu SR, it may cancel the SL SR, for example, when or if the WTRU receives a Uu grant, the WTRU may cancel the other SR. For example, the WTRU may cancel the other SR as long as there is no additional data associated with non-duplicate data to be sent on the link associated with the SR to be canceled.

[0137] The remote WTRU may be configured with SR resources for repeated data. In one embodiment, the remote WTRU may be configured with SR resources to be used when data arrives on an LCH associated with repeated data. For example, if data arrives on an LCH associated with one or more LCHs that are repeated for SL and Uu, the WTRU may send an SR on one of the dedicated SR resources associated with the repetition.

[0138] In an embodiment, when repetition is disabled, the remote WTRU may use the SR resources configured for the LCH associated with the repeated data to trigger an SR when the data arrives. For example, the WTRU may be configured with specific rules or conditions to allow the use of repeated SR resources to trigger an SR when repetition is disabled, such as: the priority of the data is above a threshold; the SL channel busy rate (CBR) is above a threshold, and data arrives at the SL LCH; the load of the relay WTRU is above a threshold, based on, for example, the receipt of a flow control message, and data arrives at the SL LCH; and the time until the next non-repetitive SR configured is above a threshold.

[0139] Although the SR associated with the duplicate data is signaled by, for example, sending another SR or sending a MAC CE after the transmission of the SR, the WTRU may signal that there is no duplicate data.

[0140] The remote WTRU may provide information related to SR / BSR coordination to the relay WTRU. The remote WTRU may send SR / BSR coordination information to the relay WTRU. For example, the remote WTRU may provide information about a SL LCH or LCG indicating the LCH or LCG for which duplication is performed on the SL (relay) path and the Uu (direct) path. Such information may be provided from the remote WTRU to the relay WTRU, for example, via PC5-RRC in the SL LCH configuration. For example, such information may be provided in a MAC CE (e.g., in a bitmap). For example, such information may be provided in a MAC header associated with a SL transmission corresponding to a repeated LCH.

[0141] The remote WTRU may send coordination information when it is reconfigured by the network. The remote WTRU may send coordination information when the repetition behavior at the remote WTRU changes. For example, if the network enables repetition between SL and Uu at the remote WTRU or changes the repetition configuration, the remote WTRU may send repetition information to the relay WTRU. The remote WTRU may notify the relay WTRU if the remote WTRU enables or disables repetition for a pair of LCHs.

[0142] The remote WTRU may send coordination information when it moves in or out of coverage. The remote WTRU may send coordination information when it configures or deconfigures multipath.

[0143] The remote WTRU may explicitly send coordination information to the relay WTRU. For example, the remote WTRU may indicate any one or a combination of the following (e.g., in PC5-RRC): if the WTRU may be configured with different resource modes for different SL LCH transmissions, the resource allocation mode of the remote WTRU that may be associated with a specific logical channel on the sidelink (e.g., mode 1 or mode 2 transmission); enabling / disabling or configuring repeated SL LCHs; whether to report Uu BSRs and / or SL BSRs to the network associated with one or more LCHs, and / or the amount / percentage of BSRs reported or still to be reported; and whether Uu SRs and / or SL SRs are triggered to the network, which may be associated with one or more LCHs.

[0144] The remote WTRU may process the coordination information and may send an indication of the SR / BSR behavior to be performed by the relay WTRU. For example, the remote WTRU may send an indication of whether a Uu SR / BSR should be sent by the relay WTRU, which may be associated with some LCHs. For example, if the remote WTRU is configured to be in mode 1, the remote WTRU may indicate to the relay WTRU not to send the SR / BSR. For example, if the remote WTRU is configured to be in mode 2 and repetition is enabled for at least some bearers at the remote WTRU, the remote WTRU may indicate to the relay WTRU not to send the SR / BSR for the SL LCH associated with the repetition. For example, if the conditions for the relay WTRU to give up sending the SR / BSR are not met, the remote WTRU may send an indication to the relay WTRU that the relay WTRU should send a BSR. In this case, the remote WTRU may not send an indication.

[0145] Without loss of generality, the above information may also be provided by the gNB to the relay WTRU and the same implementation scheme may apply.

[0146] The remote WTRU may determine whether to send an SR / BSR for Uu data. In an embodiment, the remote WTRU may determine whether to send an SR / BSR itself, or whether to rely on the relay WTRU to perform the SR / BSR transmission of Uu data associated with the repetition. For example, given that the relay WTRU and the remote WTRU are served by the same scheduler, the relay WTRU may provide buffer status information to the network to allow the network to schedule the remote WTRU on the Uu link.

[0147] The remote WTRU may determine whether to send an SR / BSR for Uu data based on one or a combination of factors or conditions, such as SL transmission mode, Uu RSRP, Uu SR configuration, SL measurements received from the relay WTRU and / or SL flow control, and preferences from the relay WTRU.

[0148] The remote WTRU may determine whether to send an SR / BSR for Uu data based on the SL transmission mode. For example, the remote WTRU may send an SR / BSR for Uu data associated with repetition only when Mode 2 resource allocation is configured.

[0149] The remote WTRU may determine whether to send an SR / BSR for Uu data based on the Uu RSRP. For example, the remote WTRU may send an SR / BSR when the measured Uu RSRP is above or below a threshold.

[0150] The remote WTRU may determine whether to send an SR / BSR for Uu data based on the Uu SR configuration. For example, the remote WTRU may be configured with no Uu SR. Alternatively, the remote WTRU may be configured with insufficient Uu SR, where sufficient UuSR may correspond to Uu SRs of a priority allowed for data for which the remote WTRU must send an SR. If the remote WTRU is configured with no Uu SR, it may rely on the relay WTRU to send an SR and / or BSR. For example, the remote WTRU may subtract the buffer status of the Uu transmissions for which the relay WTRU will report a BSR (e.g., BSRs for duplicate Uu and SL data) from any BSR report on Uu.

[0151] The remote WTRU may determine whether to send an SR / BSR for Uu data based on SL measurements and / or SL flow control received from the relay WTRU. For example, if the SL CBR is above or below a threshold, the remote WTRU may send an SR / BSR, otherwise, it may rely on the relay WTRU to send an SR / BSR.

[0152] The remote WTRU may determine whether to send an SR / BSR for Uu data based on a preference or indication from the relay WTRU. For example, the relay WTRU may indicate that it prefers or does not prefer to send an SR / BSR, and the remote WTRU may determine whether to send an SR / BSR based on the preference of the relay WTRU. For example, if the relay WTRU prefers to send an SR / BSR, the remote WTRU may not send an SR / BSR.

[0153] The relay WTRU may determine whether to trigger a SR / BSR based on information from the remote WTRU.

[0154] The relay WTRU may cancel the SR / BSR after receiving an indication from the remote WTRU indicating cancellation of the SR / BSR or providing SR / BSR coordination information. For example, the relay WTRU may receive an indication that the Uu SR / BSR should not be triggered. After receiving such an indication, the relay WTRU may cancel the triggered Uu SR / BSR whenever uplink data arrives at the relay WTRU for any LCH associated with the relay from the remote WTRU.

[0155] For example, a relay WTRU may receive an indication that a remote WTRU is in Mode 1 transmission. Upon receiving such an indication, the relay WTRU may not trigger an SR / BSR after receiving any data from the remote WTRU that would normally trigger an SR / BSR, but may trigger an SR / BSR for other remote WTRUs and / or for the relay WTRU's own data.

[0156] For example, the relay WTRU may receive an indication that the remote WTRU is in mode 2 and a set of SL LCHs for the remote WTRU are repeated on Uu. When the relay WTRU receives data from the remote WTRU on the indicated SL LCH, the relay WTRU may not send an SR / BSR, but if the relay WTRU receives data from another LCH from the remote WTRU or from another remote WTRU, the relay WTRU may trigger an SR or send a BSR.

[0157] The relay WTRU may determine whether to cancel or send an SR, and / or whether to send a BSR (and the amount of BSR data to send) based on a mapping or association. The mapping or association may be an adaptation layer mapping or association. For example, for a given Uu LCH that may or may not trigger an SR / BSR, the relay WTRU may determine whether to trigger an SR / BSR based on indications or information received from all WTRUs and LCHs multiplexed onto the same Uu LCH. For example, if at least one remote WTRU connected to a relay WTRU whose SL LCH is mapped to the Uu LCH in question does not indicate cancellation of the SR associated with the SL LCH mapped to the Uu LCH (or at least one remote WTRU indicates not to cancel the SR), the relay WTRU may trigger an SR / BSR. The relay WTRU may calculate or determine the BSR to be reported for the Uu LCH by calculating or determining only the portion of data received from the WTRU that does not indicate cancellation of the SR / BSR.

[0158] In an embodiment, the relay WTRU may determine to trigger a SR / BSR based on information from the remote WTRU and / or the network. Fig. 9A method 900 for triggering and sending an SR / BSR for a relay WTRU is shown. The relay WTRU may receive multipath information 910 from a remote WTRU. The information may be a PC5-RRC message. The information from the remote WTRU may indicate a set of SL LCHs associated with the repeated data. The information from the remote WTRU may indicate a resource allocation mode (e.g., mode 1 or mode 2) of the remote WTRU. The indication of the set of SL LCHs associated with the repeated data and the indication of the resource allocation mode may be in the same message or in separate messages. The relay WTRU may receive multipath information from multiple remote WTRUs.

[0159] The relay WTRU may receive information from the network regarding the association or mapping of the SL LCH (or LCG) to the Uu LCH (or LCG) 920. The information from the network may be adaptation layer configuration information. For example, the information may be received in an RRC message.

[0160] The relay WTRU may determine whether to trigger an SR / BSR 930. For example, the relay WTRU may trigger an SR / BSR when data arrives at the relay Uu LCH and under the condition that at least one remote WTRU (having an SL LCG mapped to or associated with the relay Uu LCH) is configured with mode 2 and at least one of the SL LCHs mapped to the Uu LCH with available data is not associated with duplicate data.

[0161] The relay WTRU may calculate or determine the content or parameters of the SR / BSR 940. The relay WTRU may calculate or determine the content of the BSR based on the multipath information from the remote WTRU (or remote WTRUs) and the information from the network. The relay WTRU may calculate or determine the content of the BSR for the relay Uu LCH as the amount of data to be sent, which is mapped to or associated with the SL LCH that is not associated with duplicate data and is associated with mode 2 transmission. The BSR may inform the network about the amount of uplink data in the WTRU. For example, the content or parameters of the BSR may include, but are not limited to: the amount of uplink data for the logical channel, the identification of the logical channel and / or logical channel group, the buffer size field, the total amount of uplink data available, the total amount of uplink data available for logical channels across logical channel groups, and / or an index indicating the buffer size value. The WTRU uses the SR to request uplink shared resources for new transmissions.

[0162] The relay WTRU may send a SR / BSR 950. The SR / BSR may be sent to the network, which may be a gNB. The SR may be sent, for example, on the PUCCH. The BSR may be sent, for example, in a MAC CE on the PUSCH.

[0163] Although features and elements are described above in specific combinations, it will be understood by those of ordinary skill in the art that each feature or element may be used alone or in any combination with other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (sent via a wired or wireless connection) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media (such as built-in hard disks and removable disks), magneto-optical media, and optical media (such as CD-ROM disks and digital versatile disks (DVDs)). A processor associated with software may be used to implement a radio frequency transceiver for a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

1. A method implemented by a relay wireless transmit / receive unit (WTRU), the method comprising: receiving information from at least one remote WTRU, wherein the information from the at least one remote WTRU comprises an indication of a set of sidelink (SL) logical channels (LCHs) associated with repeated data and an indication of a resource allocation pattern of the at least one remote WTRU; receiving information from a network, wherein the information from the network includes an indication that a SL LCH is associated with a Uu LCH; triggering a buffer status report (BSR) when SL LCH data associated with the Uu LCH of the relay WTRU arrives from at least one remote WTRU having a mode 2 resource allocation pattern and on the condition that at least one SLLCH from the at least one remote WTRU having a mode 2 resource allocation pattern is not associated with duplicate data; determining parameters of the triggered BSR for the Uu LCH of the relay WTRU based on an amount of data to be sent from the at least one SLLCH of the at least one remote WTRU having a resource allocation pattern of mode 2, the at least one SLLCH not being associated with duplicate data; as well as The triggered BSR with the determined parameters is sent.

2. The method of claim 1, wherein the resource allocation mode of the remote WTRU is mode 1 or mode 2.

3. The method according to any one of claims 1 or 2, wherein the information comprising the indication that the SL LCH is associated with the UuLCH is an adaptation layer configuration.

4. The method according to any one of claims 1 to 3, wherein the information received from at least one remote WTRU is a PC5-Radio Resource Control (RRC) message.

5. The method according to any one of claims 1 to 4, further comprising: A parameter of the triggered BSR for the Uu LCH is determined as the amount of data to be transmitted associated with the at least one SLLCH in the SL LCH mapped to the Uu LCH having available data.

6. The method according to any one of claims 1 to 5, further comprising: The BSR for remote WTRU data is cancelled upon the relay WTRU receiving an indication from the remote WTRU to cancel the BSR.

7. The method according to any one of claims 1 to 6, further comprising: The BSR for remote WTRU data is cancelled upon the relay WTRU receiving an indication that the remote WTRU is performing resource allocation Mode 1 transmission.

8. The method according to any one of claims 1 to 7, further comprising: The parameters of the triggered BSR are determined based on the SL LCH data from the remote WTRU that did not indicate cancellation of the BSR.

9. A method according to any one of claims 1 to 8, wherein the remote WTRU sends information to the relay WTRU: when reconfigured by the network, the repetitive behavior of the remote WTRU is changed, or the remote WTRU moves into or out of coverage.

10. The method according to any one of claims 1 to 9, further comprising: A determination is made by the remote WTRU whether to send a BSR, wherein the determination is based on a resource allocation pattern, Uu reference signal received power (RSRP), Uu scheduling request (SR) configuration, SL measurements, or a preference from the relay WTRU.

11. A relay wireless transmit / receive unit (WTRU), the relay WTRU comprising: Receiver; Transmitter; and A processor, wherein: the receiver being configured to receive information from at least one remote WTRU, wherein the information from the at least one remote WTRU comprises an indication of a set of sidelink (SL) logical channels (LCHs) associated with repeated data and an indication of a resource allocation pattern of the at least one remote WTRU; The receiver is further configured to receive information from a network, wherein the information from the network includes an indication that the SL LCH is associated with the Uu LCH; The processor is configured to trigger a buffer status report (BSR) when SL LCH data associated with the Uu LCH of the relay WTRU arrives from at least one remote WTRU having a mode 2 resource allocation pattern and on the condition that at least one SL LCH from the at least one remote WTRU having a mode 2 resource allocation pattern is not associated with duplicate data; The processor is further configured to determine parameters of the triggered BSR for the Uu LCH of the relay WTRU based on an amount of data to be sent from the at least one SL LCH of the at least one remote WTRU having a resource allocation pattern of Mode 2, the at least one SL LCH not being associated with duplicate data; and The transmitter is configured to transmit the triggered BSR with the determined parameters.

12. The WTRU of claim 11, wherein the resource allocation mode of the remote WTRU is mode 1 or mode 2.

13. The WTRU according to any one of claims 11 or 12, wherein the information including the indication that the SL LCH is associated with the Uu LCH is an adaptation layer configuration.

14. The WTRU of any one of claims 11 to 13, wherein the information received from at least one remote WTRU is a PC5 - Radio Resource Control (RRC) message.

15. A WTRU according to any one of claims 11 to 14, wherein the processor is further configured to determine a parameter of the triggered BSR for the Uu LCH as the amount of data to be sent associated with the at least one SL LCH in the SL LCH mapped to the Uu LCH having available data.

16. The WTRU according to any one of claims 11 to 15, wherein the processor is further configured to cancel the BSR for remote WTRU data if the relay WTRU receives an indication to cancel the BSR from the remote WTRU.

17. The WTRU according to any one of claims 11 to 16, wherein the processor is further configured to cancel the BSR for remote WTRU data if the relay WTRU receives an indication that the remote WTRU is performing resource allocation mode 1 transmission.

18. The WTRU of any one of claims 11 to 17, wherein the processor is further configured to determine parameters of the triggered BSR based on SL LCH data from a remote WTRU that does not indicate cancellation of the BSR.

19. A WTRU according to any one of claims 11 to 18, wherein the remote WTRU is configured to send information to the relay WTRU: when reconfigured by the network, the repetitive behavior of the remote WTRU is changed, or the remote WTRU moves into or out of coverage.

20. A WTRU according to any one of claims 11 to 19, wherein the remote WTRU is configured to determine whether to send a BSR based on a resource allocation mode, Uu reference signal received power (RSRP), Uu scheduling request (SR) configuration, SL measurement, or a preference from the relay WTRU.

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